Advanced Machines

[Canuck]

Couple of tips...on the bigger advance machines,what Canon has done is eliminate lots of clutches(vertical transport for example) and use stepping motors. Change speed,blah,blah. The thing about a stepping motor...put a load on it and it stalls. Older models,honking big dc motors with clutches,maybe some monitoring of rotation. Can't stall these. Things keep turning until you blow a gear. I have solved MANY jamming problems on these machines(6055,7055,paper deck jamming issues,etc) by cleaning the bushings on the drive units,or the bushings for the shafts that they turn(vertical rolls,delivery drive,duplex drive). Canon has issued replacement bearings for most of the bushings. It does not take much resistance to stall the stepping motors. Any intermittent jams associated with rolls,etc driven by stepper motors....clean the bushings or put in bearings. I have a lot of these machines that have millions of copies on them and have seen this many,many times. Delivery area is the most notorious. Had a few that stiff vertical rolls would prevent motor from even turning. Turned by hand,but a little snug. It will seem like the motor is toast or a board is toast. Amazed me the first time i ran into it a couple years ago. A tool I use on bigger machines(7105,8105,6075s) is my cell phone camera. I cheat the front and video record paper as it passes through. Hard to see whats exactly going on at 105 sheets per minute. I take the video,load it on my laptop,then play it with vlc player. VLC has frame by frame advance and you can see the paper move frame by frame through the machine. Had a 7105 drive me nuts before with duplex jams(intermittent,1 every thousand,which is one every 10 min on 7105...not acceptable).By viewing it frame by frame, I could see it lose separation once in a while. Very helpful. Just FYI

[vigour]

amazing work pal!!!

Great explanation.
I wondered why they jam, when you can barely feel the difference between a bad and good drive.